In general, sensing elements of micro-electromechanical sensors are required to be operated in a specific circumstance to achieve desired optimal performance. Thus, operating circumstances of the sensing elements are adaptable to meet different functions of the micro-electromechanical sensors to ensure a high sensing accuracy. For example, for some micro-electromechanical sensors (e.g., a gyroscope), a damping effect to the vibration frequency and noise-to-signal ratio need to be considered. Hence, the sensing elements (e.g., a movable mass in the gyroscope) thereof are disposed in a vacuum hermetically sealed chamber to reduce the effect of air damping. Some other sensing elements (e.g., a movable mass in an accelerometer) requires appropriate air damping when vibration is generated during measurement of acceleration, so as to obtain correct results. Therefore, the sensing elements (e.g., the movable mass of the accelerometer) thereof need to be disposed in a hermetically sealed chamber with a specific gas pressure. Furthermore, some further sensing elements (e.g., a sensing film of a barometer need to be enclosed in a hermetically sealed chamber with a specific gas pressure or a vacuum hermetically sealed chamber, so as to measure an atmospheric pressure of the circumstance where the barometer is located.
However, owing to the requirements on smaller size and lower cost of electronic devices on the market, integration of sensors with different functions becomes a main trend in developing micro-electromechanical sensors. Thus, providing a micro-electromechanical sensor with multiple chambers to allow different sensing elements to achieve the optimal performance at different gas pressures has now become a crucial part in integrating multiple micro-electromechanical sensors.